usb: gadget: always update HS/SS descriptors and create a copy of them

HS and SS descriptors are staticaly created. They are updated during the
bind process with the endpoint address, string id or interface numbers.

After that, the descriptor chain is linked to struct usb_function which
is used by composite in order to serve the GET_DESCRIPTOR requests,
number of available configs and so on.

There is no need to assign the HS descriptor only if the UDC supports
HS speed because composite won't report those to the host if HS support
has not been reached. The same reasoning is valid for SS.

This patch makes sure each function updates HS/SS descriptors
unconditionally and uses the newly introduced helper function to create a
copy the descriptors for the speed which is supported by the UDC.

While at that, also rename f->descriptors to f->fs_descriptors in order
to make it more explicit what that means.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/usb/composite.h b/include/linux/usb/composite.h
index 8634a127bdd3..b09c37e04a91 100644
--- a/include/linux/usb/composite.h
+++ b/include/linux/usb/composite.h
@@ -119,7 +119,7 @@ struct usb_configuration;
 struct usb_function {
         const char                      *name;
         struct usb_gadget_strings       **strings;
-        struct usb_descriptor_header    **descriptors;
+        struct usb_descriptor_header    **fs_descriptors;
         struct usb_descriptor_header    **hs_descriptors;
         struct usb_descriptor_header    **ss_descriptors;
 
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 5b6e50888248..0af6569b8cc6 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -939,6 +939,13 @@ static inline void usb_free_descriptors(struct usb_descriptor_header **v)
         kfree(v);
 }
 
+struct usb_function;
+int usb_assign_descriptors(struct usb_function *f,
+                struct usb_descriptor_header **fs,
+                struct usb_descriptor_header **hs,
+                struct usb_descriptor_header **ss);
+void usb_free_all_descriptors(struct usb_function *f);
+
 /*-------------------------------------------------------------------------*/
 
 /* utility to simplify map/unmap of usb_requests to/from DMA */